Fire-alarm signal



May 27, 1930.-

E. c. J. BOLIILLON FIRE ALARM SIGNAL Filed Sept. 28, 1926 Patented May 27, 1930 UNITED STATES PATENT OFFICE EMILE CELESTIN JEAN IBOUILLON, OI PARIS, FRANCE, ASSIGNOR TO SOCIETE BOUIL- LON FaEnEs, or

PARIS, rnANoE' FIRE-ALARM sI'GNAI.

Application file September 28, 1926, Serial No. 138,309, and in France October 2, 1925,

The present invention relates to fire-alarm signal systems and aims to provide an' apparatus which is simpler and more widely applicable than those now in use.

Most fire-alarm systems are designed to give a signal only after a predetermined temperature shall have been exceeded. Other systems function only during abrupt temperature changes. In all of these systems, the apparatus is either very fragile or very complicated, barometric correcting devices and other intricate auxiliaries being generally necessary.

The object of the present invention is to provide an apparatus capable of functioning under any and all circumstances involving danger from fire.-

Another object is to provide a device capable of giving a signal with both slow and rapid changes of temperature.

A further object is to provide an apparatus free of all auxiliaries and capable (1) of setting otf simple or multiple light, sound or other types of signals, or of controlling automatic fire extinguishing apparatus through appropriate electrical circuits.

A still further object is to provide a device capable of being adjusted by mere displacement of an index on a dial to respond to any temperature limit desired.

Other objects will appear in the'course of the detached description which will now be given with reference to the accompanying drawing in which:

Figure 1, is an elevation of one form of the invention.

Figure 2, illustrates, in plan, the device shown in Figure 1 Figure 3 is a section taken on the line w-a: of Figure 1;

Figure 4 represents in section the assembly of the casing and the interior mechanism; Figure 5 is a view in detail;

Figure 6 represents in partial sectiona second embodiment of the invention;

Figure? is a plan of the device shown in Figure 6.

The embodiment represented in Figures 1 to 5 comprises a hollow circular casing 1 to which a square block 2 is centrally attached by means of a screw or in any other convenient manner. Block 2 carries two spiral bimetallic elements 3 and 4 as shown in Figure 3. Each bi-metallic element is made up of metals having as great'a difierence in coefficient of expansion as possible. The metal having the lesser coefficient of expansion is placed on the inner side of the spiral. Spiral element 3 (the one which is the further from the center) is insulated by block 13 from element 4 and carries a contact 5 at its free extremity. The upper portion of casing 1 is formed with an extending portion 1 (Figure 4) which serves as guide for a second hol-low casing 6 adapted to fit over casing 1. Casing 6 encloses the lei-metallic spirals and is perforated so that the latter respond rapidly to temperature changes outside the casing.

Casing 6 may be rotated about block 211s an axis, the latter being made cylindrical at its upper extremity. The upper surface of easing 6 is provided with a dial 7 which moves with the casing relatively to a fixed reference mark 7 cut on a washer 8 held in place on block 2 by screw 9.

A contact cam 10 is fixed by rivets or otherwise to the inner portion of movable casing 6.

Spiral 3 is in circuit with a terminal 11 properly insulated from the casing, while spiral 4 and cam 10 are in conductive relation with terminal 12 connected directly with the casing.

The apparatus, as thus constrpctedflfupcff tions in the followin way.

If the device is su jected to a slow change of temperature, the curvatures of each of the spirals changes in proportion to the difference of coefficient of expansion of the component metals. v

The metal having the greater co'eflicient of expansion tendsv to move the spirals back to normal, but the sections of the latter may be so chosen that the two spirals remain substantially parallel. If then, the spirals are slowly heated to a chosen temperature limit, contact 5 will touch cam 10 and complete the circuit between terminals 11 and 12. The signal or extinguisher circuit connected to 11, 12 will then respond.

The position of cam 10 is determined by the the latter.

relative positions of dial 7 and reference mark 7 By varying the angular displacement 7, 7', earn 2 may be made to approach or move away from contact 5. Dial 7 may be calibrated to read temperatures directly and the apparatus may be adjusted to respond at any temperature limit desired.

In the event that the device is subjected to a rapid change of temperature, spiral 4, which has a smaller section than spiral 3, becomes heated more quickly and deforms itself more rapidly.. As a consequence, spiral 4 contacts with contact 5 before spiral 3 has attained the temperature limit and the circuit between 11 and 12 is closed since each spiral is connected to each of these terminals.

In the modification shown in Figures 6 and 7, the device is made up in a single perforated casing 14, enclosing two parallel, rectilinear bi-metallic strips. Strip 4 is the thin-- ner of the two and is in conductive relation to the casing and to terminal 12 connected to Strip 3 is insulated by block 13 and is in circuit with insulated terminal 11.

The regulating effect is obtained by means of a cam 10 of convenient design which may be adjusted by milled element 15 placed outside the casing so as to vary its distance from contact 5 situated at the end of strip 3. In the drawing, contact 5 is shown with a rear prolongation 17 serving to reduce the effective distance between the strips while insuring a suflicient space between the latter to avoid any ill-timed contact. Adjusting screw 15 has a reference mark 7 which moves opposite a dial 7 and permits direct regulation of the temperature limit as already described. The apparatus is completed by proper batteries and luminous or sound signals properly connected in circuit with terminals 11, 12.

This modified apparatus functions in a manner similar to the device illustrated in Figures 1 to 5. With slow temperature change, strip 3' moves into contact with cam 10 and sets off the signal. In case of. rapid prising, in combination, a circular support having a raised center portion, a block carried by said center portion, a pair of spiral thermally responsive elements fixed at one extremity to said block and insulated from each other, a circular casing for enclosing said elements, said casing being rotatable about said raised center portion, a cam segment fixed to the wall of said casing and adapted to coact with the free'extremity of one of said thermally responsive elements, a member; carried by the casing having indicia thereon, and means carried by the block for cooperating with said indicia to indicate the temperature of operation of the apparatus.

2. An apparatus of the class described comprising, in combination, a circular support having a raised center portion, a block carried by said center portion, a pair of spiral thermally responsive elements having one extremity thereof fixed casing for enclosing said elements; said casing being rotatable about the raised center portion, and a contact cam segment carried by the wall of said casing whereby to vary the time of contact between the free extremity of one of said thermally responsive elements and the cam surface incident to rotation of said casing.

3. An apparatus of the class described comprising, in combination, a circular support having a raised center portion, a block carried by said center portion, a pair of spiral thermally responsive elements having one extremity thereof fixed to said block, a circular casing for enclosing said elements, said casing being rotatable about the raised center portion, and a contact cam segment associated with the said casing whereby to vary the time of contact between the free extremity of one of the said thermally responsive elements and the cam surface incident to rotation of the said casing.

In testimony whereof I aflix my signature.

EMILE CELESTIN JEAN BOUILLON.

change of temperature, strip 4 deforms rapidly and .makes an end to end contact with strip 3 through contact 5 before the latterreaches cam 10, thus setting off the alarm. The adjusting in both forms of the apparatus is by cam and therefore progressive 1n character. The alarm is compact and free of structures capable of gripping or looking.

The bi-metallic strips are sensitive and deendable and the assembly such that there is but slight possibility of the sensitive parts of the apparatus being damaged or disturbed in'adjustment. Having now particularly describedand ascertained the nature of my said invention and in what manner the same is to he performed,-

I declare that what I claim is:

1. An apparatus of the class described com- 

